Automatic call-distributer system.



F. R. MOBERTY. AUTOMATIC GALL DISTRIBUTER SYSTEM APPLIG'ATICN FILED JAN`6,1913.

Patented Sept. 15, 1914 2 SHEETS-SHEET 1.

F. R. MGBERTY.

AUTOMATIC C ALB DISTRIBUTER SYSTEM.

APPLICATION FILED JAN. 6,1913.v

1, 110.809p Pater/ima sept. 1511914 2 SHEETS-#SHEET 2 if? HIV JV/messes:

Y To all :who/n. t may concern the Jfollowing UNITED sTATEs PATENT oEEICE.

FRANK E. MCBERTY, OE ANTWEEP, BELGIUM, AssIGNOE To WESTERN ELECTRIC COMPANY, OE NEW YORK, N. Y., A CORPORATION OE ILL1No1s.

AUTOMATIC CALL-DISTRIB UTER SYSTEM.

Be it vknown that I, FRANK R. MCBERTY,

va citizen of the United States,v residing'at Antwerp, in the Province of Antwerp and Kingdom of Belgium, have invented a certain new and .useful Improvement in Automatic Call-Distributer Systems, 'of which exact description.

#This Invention relates to c1rcu1t arrangements and mechamsm for establlshlng a suitable connection fronione of a group [of lines' to another line, and its Object isl to pro# vide an improved system of this kind capable -with great facility of establishing the desired -connectionsyand of avoiding simultaneous Connections being maintained with the same line'.

In accordance with the invention, the ap- I para-tus vis so arranged and connected that, although 'several group lines may by chance be connected simultaneously to theother line, only one of the grouplines can remain so Connected.v -The selecting process, by

means of which O nlyone group line can getv effectively connected with another line and remain connected therewith, may be con'- vtrolled by various means but preferably relays, one for each line, are 11'sed. Any num-,.

ber of these relays maybe simultaneously energized. IVhenever this happens they arev brought into a common circuit-in which but' one can remain energized.

The -inventionis of especial advantage in' telephone systems where there are many points at which a plurality of lines are to be connected eachv with a single line. In wellT .known systemsthere is required not only the -apparatus for connecting a certain line of the Agroup `(hereinafter designated as an' incoming line)v to the'other line (hereinafter designated as `the outgoing line), but also special arrangements to prevent more than one incoming'line from making connection to the outgoing line. Conditions,

operators or switches so that simultaneous orpractically simultaneous connections are occasionally made to a single outgoing line,

.and the invention is especially useful in taki lSpecification. of Letters Patent. c

' apparatus,

is-,a full. clear, concise, and c Y V l 1s only one of many well-known` type,

Patented sepe15, 1914.

lApplieaticnl led January 6, 1913. Serial No. 740,497.

whereas F ig. 2 illustrates apparatus and circuits associated with a Connecting cn-cuit, and an operator-s telephone. The two drawings when taken together represent so much of an automatic telephone exchange system as .fulldisclosure of the invention, it being understood ofcourse that the system described types lin which the invention may. find useful embodiment.

In the drawing is shown a system of cir- 'cuits and apparatus wherein only one of. the incoming a lsubscriber T. de'sirejsla connection he removes` his receiving telephone from the hook andthereby closes a circuit from battery 2 in the central oilice through line relay 3, con: tact-37 of' cutoff relay 36, to wire '4 of the calling line, thence through the substation transmittenhool: switch 6, induction coil 7, to the other wire 8 through contact 9- ofthe cutoff relay 36 to' ground or other side of battery 2. vLine relay 3 operates closing a circuitat its contact 1,0 from battery 11, through the starting relay 1,2, said contact 10 and resistances 13' and 14 to ground.- Y

The operation of starting relay 12 closes at its contact 15 ya ground connection to a common starting wire 16. This common wire 16 is Connected, as will be presently explained, to starting devices which serve to connect the calling'lin'e with an operators position. These devices include switches A S calledline Iinders which may be of any' but that type is shown the wipers or moving brushes of which are opl erated by an electromagnetic coupling with a power shaft.- "It is similar to the switch for automatic telephone exchanges described `in my application',` Serial No. 573,516 filed July 23, 1910. AThe electromagneticcouphng of those line finders A Sgeoperates to connect the brushes or wipers with a con- .60 seems necessary for' a l' y calls from `subscribers may be'v .transferred to an operator at a timel and .that only in case the operator is 'freel When `70,

of the line, and

tinuously revolving power shaft. AThe se-wquence of the switching operations is in this system controlled in its various phases by .so-called sequence switches which `may be like or similar to that dis-closed in Patent. No. 1,009,080 issued November 21, 1911.

All line .lindersA S adapted to serve a certain group of subscribers" lines are-connected to the common wire 16. l This is accomplished Jfor each line nder thmugh spring contact 17 whichis closed in position 1 (the normal position) of the sequence switch of that line finder. The branch Wires', 5. to common wire .16 indicate connections to like sequence switch contacts 17 of other line finders., Whenl contact of thestart ing relay12 is closed in the. above described l manner, the clutch magnets l) of all line l@ finders A S, whose sequence switchesl are at hat time in their No. 1y orl home positions, receive current through common wire 16 and contacts17, the circuit for each such magrelay, a certainbattery potential, .dilierent from tv e norm lor ground potential, was put `onfontact 2,2. ,Through wiperf21 of hat, line'inder ;-A S,iwhioh first .arrives at 'such' contactl or alnultiple thereon-.the following circi'iitjfpisv established z-Battery 11.. relay 12, contat t2'10, resistance 13, contact 22, wiper 2151 contact 23 of the sequence switch (position 1), a high resistance wind 25, andcontact brush ing -21of test relay 27 which travels. over a toothed metal. .piece 2,6 connected' to ground, this circuit being intermittently completed byengagement of brush 27 with the teeth of the piece 265. The brush- 27 is carried with the movable wipers roof thelineufinder, and the toothed metal- A v piece 26 isxed on the ramef'thereof. ',The J brushmakes contact with the teeth during l the intervals of time that the wipers. 18 toy 21 are passing between successive sets oflinevvv contacts, and restsbetween the teeth and out of contact with the metal piece `only, when the brushes are in contact with and'centrally positionedon av set 'of line contacts. Relay 25 operates when' the line calling is' thus found'iand connects its low resistance winding 28 in shunt ofv the high resistance winding. 24. AAt the same timeA the brush .2 7 comes to rest thereby opening a shortrcircuitoffthe relay 29. The cutting in offwinding1-28'effectsa drop of the which prevents any other one' of the line finders set in motion from stoppingon .the same line. The relays 25 are made marginal.,

.60 thus if by chance the brushes oftwo or more n line finders should arrivefsimultaneously on. the contacts V'of a calling line andtherc sresponding relays 25v shouldibec'ome enerf. Igized, the'zcuttingin ofv the low resistancer winding will cause a decrease in the holding p in a notchin the pieceb26,

voltage at. the test contact 2 2` Limena power of these relays so that only one will Y be v,maintained energized. This dropping olf got altibut one of 4the relays25 will occur.

before the short circuits of the relays 2,9 are interrupted, thus''only the relay v29 associa-ted lWith that relay 25 which has been maintained actuated. will be energized.

-When relay 29 becomes energized .it interrupts at its back contact 30, the circuit of the clutch magnet'D of the line nder now in connection with the calling line, thereby stopping further. motiono its wipers.

Simultaneously with the interruption of i the circuit through D alcircuit is closed for magnet lS 'of `a line finder sequence switch,

this circuit being from battery through S,

j sequence switch contact 32v (position 4.1), u front contact 310i relay 29, sequence switch contact 17 .(position l1) contact 15.to ground. Atthe same time azcircuit is established for stop magnet`Q of thefline finder A S, the path for this magnet being in parallel circuit with magnet S. The sequence switch is thereupon--advanced to position-3, the .cir-

cuitiof magnet S being maintained in position v2'by'contact l38. During the advance@ ment of thesequence switch, the initial circuit for S is interrupted at' contact In vpassing position 2 relay 2,9 is short-circuitedby v sequence switch contact 33 and cutof relay 36 is a'lso'operated` over a circuit Jfrom battery, relay36, a contact closed by wiper l20, sequence switch, contact 34 (position 2),

the windings 24 and 28, of `relay 25 in Inulti--` y y ple, sequence 'switch {contact-33 toground. A branch ofthiscircuit maybe 'traced from :sequencelswitch contact 34,' through contact 2 3, brush ;21,'=co1itact 22, and resistance 14 to ground. n necting at contact 37 ,the line relay 3 from one side of theline and removingground atl contact 9 from the other side. vin releasinginterrupts the circuit. of relay12 hich in turn opens/its contact 15 which had maintained a .groundconnection to thel driving magnetsDof all idle line finders in vthe group. These linenders nowystonin whatever positions they happen tobe in jat that time. E 1:1

. In position 3 offthe' line finder sequence switch av circuit-is. -closedl :tromv ground through sequence switchcontact 39 (posi-v tion 3), line 40,spring 4 1of another sequence switch `(position '1) to the driving 'magnet Si of that second sequence switch to battery. .This second sequence switch, which isindividual to vthe selected link ycircuit, serves to .connect the line linder AS, now setior the calling-line, temporarily with an operative telephone. As soon as the above mentioned circuit through magnet S1. :is closed, the second sequence switchad- ,vances to atsl second ,position thereby closing ,hej following circuit; From battery,

throu h. sequence: switch contact'f12 (posiibo Cuto'-relay operates discon-v 105 I Line relay 3 y tion 2), winding 43 of starting relay 44,

which is individual to the selectedlink eireuit, wire 45 leading to the operators posi- 44. All these relays tion P, thence through spring 46 of a third' sequence switch (in position 1)- associated with that operators position, and back contact 47 of relay 48 to ground.

` Associated with each line finder of an operators position is a starting relayy such as relays 44 and 44 corresponding to relay are connected to wire 45. It may be assumed that a plurality of these starting relays, for example, three of them areconnected simultaneoulsy to the above-mentioned -wire 45 due to the closure by their respective sequence switches at practically the lsame moment of theseveral contacts corresponding `to contact 42', there being one such contact associated with each :line finder sequence switch. 'All of such relays which-happen to be simultaneously energized will have current flowing in their windings corresponding to windings 43, and each will close a circuit for its other winding.

quence switch contact 49 (position 1), a high resistance 50, winding of relay 48, operators sequence switch spring 51, wire 52, and

thence through the front contact 53 andthe winding 54 of starting relay 44, sequence` switch spring 55 and a relay 66 to battery. Other starting Arelays simultane.

ously energized close multiple branches in the same circuit, so that all of the windings of such relays are in parallel and fed through the commonv resistance 50. Thereupon .relay 48 is operated which, by opening contact 47, removes ground' from the wire 45. thereby interrupting the current in the windings 43 and corresponding windings of the several vstartingv relays. At this time windings 54, 54', and 54, etc., of these relays receive current through sequence switch spring 49 (position 1) the high resistance 50 and relay 48. The current through the high resistance is insufficient to hold operated all the starting relays in multiple. It is a fact observed in actual operation that the armatures ofseveral relays in the same circuit do not release absolutely simultaneously. As soon as one of the armaturesreleases, the current in the windings of the remaining relays is strengthenedA a little.

Theresistances are so balanced that only` to adjust the armatures by stiiening the ll springs, etc. It may be assumed that relay v .Relay 48 closes at its back contact' 47 a cir- This circuit,l may be traced as follows:- From` ground, through the operators se '44 is that one of these relays which holds up its armature. It will be understood that the elimination of the remaining starting relays from the circuit takes place in an extremely short period of time. v

By the operation of relay 48 a circuit for the magnet S2 of the. operators sequence switchwas closed at its front contact 57, the sequence switch thereupon advancing to its second position. This switch reaches .position 2 only after all the above described operations of the starting relays have taken place. In position 2 a contact 58 short-circuits the high-resistance 50 and thereby causes such anincrease of.the current in the circuit through the relays 48, 44 and 56 that the latter relay, which had not previously been suiciently energized, also operates closing its contact 59 which completes 'a circuit for the sequence switch magnet S1. lThis sequence switch thereupon moves to position 7. In moving-to position 7 contact 55 interrupts this circuit for relays 56, 44 and 48.

cuit for sequence switch magnet S2, from battery, through S2, sequence switch conltact- 46 (position 2), and contact 47 to ground.l .This sequence switch thereuponadvancesl to position 5.' lVhile passing 95 through position 3 a circuit is closed at contact 60 from ground, through 60, wire 6l, sequence switch contact 62. (position 7), Contact 63 of the sequence switch associated with the line finder (now in position 3), and 10o y through sequence switch magnet S, thus causing the line finder sequence switch to advance tol position 4. As soon as the se- .quence switch at the operators position reaches position 5, relay 48 is again operated 105 vthrough the circuit from ground, contact 49,

resistance 50, relay 48, contact 51, wire 52, contact 60, wire 6l, contact 62, contact 63,4

n (position 4) ,and resistance 64 to battery.

The sequence switch of the line finder in position 4 connects both sides of the subscribers line through the contacts 65, 66 to the wires 67, 68, which had been connected v previously to the wires 7l, 72 by contacts 69,

70 of the sequence switch operatedv by mag- 115 net S1 in position 7. The Wires 71, 72 lead to the operators-telephone set 73. Thus a talking connection is established and the operator can ask the subscriber for the number wanted. The call is made visible to the 1120 operator bythe closure of a local circuit for the call lamp 75 at contact 74 of the operators sequence switch' in position 5. In this position of this sequence switch there is also closed a circuit for relay 56 at .con- 125 tact 76, which circuit is also led through contacts of a sequence switch of a selector W associated with the line finder AS. The

lrelay closes contact 59 and thus causes the sequence switch controlled by magnet S1 to i3@ advance to position 9 in which the talking set f the operatorrema'ins connectedto the subscribers line. i

The operator now inquires of the calling subscriber the number of the line wanted.

v After obtaining t-she sets up `this number inthe'well-known 77. a at.'- her position,

- operating Arelay 79 manner on a keyboard thereby operating the selector W and eventually other selectors. which may besupplied but are not shown. Inas'much-as these.- events arenotimmedt ately concerned with the-present invention,

adetailed .description of them will not be enteredinto. Afterthe setting up of the -niiimber onthe keyboard sender aground connection to wire 78 is established by a contact associatedI with the sender,-` thereby which closes its contact 80 which prepares for the subsequent operation-o relay 4:8. f

` As soon as the impulses produced by the sender have caused'the advance of the se- .closedthroiigh contact 80,

vagain opening: the circuitl for S;

qiience switch associated with selector W to' position 8, a contact 8l is operated there-` by closing la circuit Jfrom;ground through contact 81, wire-82, contact 32 (position 4), sequence switch magnetv S land battery. This 4seque'nceswitch thereupon advances to pos-i- `wire 78 to releaserelay 79 vwhiclianiayfha' pen at lvany time after the settinguall t e selectors is completed. In such instance the circuitxforgSZ would again be established' by the releasing of relay 48, and the sequence switch associated with the operators posil tion would be advanced from position. 8 ,to

' normal, whereupon the: `op'erators position tion *established may would be free for agnew call. The connecbe supervised and taken down at .theoperators positioninthe well-knownl mannerl w I claimz' ytablished by they said lines ing said vmeans for thereupon adjustingtheswitch- 1f In a Switehing sysiemne .Combination `with a' plurality of incoming lines, an outgoing lineand switching afpparatusfor .connecting said incoming ylines `with ysaid out going line, of means operating in case a plurality of simultaneous connections are established by thegsaid only one connection to reniainnj i 2.' `In a switcliin system -thejcoVl bination with a plurality o incoming linesan oi1t going line and switching apparatus torreon? necting said A rality of simultaneous connections are es. for permitting only oneconnect-ion to remain, said means lines' for permitting' incomingl lines with said out'- going line, of means operating lin case a pliif comprising a relay for eachv incoming line,

and a co-mmon circuit for saidrel-ays adapt- -ed to permit only one relay to remain Lener gized therein. f 3. vIn va telephone with a plurality of incoming lines,'.an outgoing line and switching .apparatus fo'r connecting said incoming .lines withv sa-idjoiitgoing line, ofmeans operating case a plu..

rality of simultaneous connections are established by the said lines for permittingonly one connection to remain,saidl means coing prisinga relay .oreach` incomingfline, a common circuit forsaid 'relays adapted to system thecoinbination permit only one relay to remain energized l therein, each of said lrelays having two windings, one ,of which is .an energizing winding and the other a holdingwinding, and means for switching said*holding-windv ing into parallel with the .corresponding windings of other simultaneouslyenerg'ized relays] Y, l

`et.. A multiple switching system comprising means for establishing simultaneously -a plurality of connections to a single Vline and means for'. thereupon adjustingA theswitch- I i ing apparatus so-that one ,connection only mayremain.' .v i

5. A switching systein,com tor establishing simultaneous of connections to a single line and connections momentarily,

rising means y a plurality `and ing apparatus so that allbut one of tHe/con- I nections .will be interrupted. l

. 4In witness whereof, I-.hereunto'siibscribe dember A. D., 1912. L --FRANKR-MGBERTY- .VVitnessesz` ELLA EDLER, v

WALTER HOFFMAN.

for ,hold- 

